People who have gone to their workplaces and performed their duties without compromise may be subject to termination solely based on the presence of cannabinoids within the detection window. At least equally if not more important, employers should consider the window of impairment particularly because it directly reflects work performance.
The paper reviewed for this column provides clinical data supporting a test for recent inhaled cannabis use that more relies on a determined window of impairment than on the detection window.
Specifically, the researchers collected blood and exhaled-breath samples (two-sample strategy) before and after cannabis-smoking sessions from 74 subjects with 3:1 ratio of males to females ranging in age from 21 to 42 years.
Test samples were analyzed using liquid chromatography high-resolution mass spectrometry (LC-HRMS) for the quantitation of delta-9 THC and other cannabinoids in microsamples of whole blood. Data were aligned with subjects’ self-reporting of impairment on a 10-point scale.
The window of impairment was determined to be approximately three hours after smoking, with approximately 8% of subjects reporting impairment that extended beyond three hours but not more than four hours. Interestingly, the presence of delta-9 THC did not conclusively demonstrate recent use within the impairment window.
Overall, the results from these studies (and more to come) pave the way toward laws that will end discrimination against people whose choose to engage in lawful activities outside the workplace.
Susan Audino, who holds a doctorate in chemistry, is a chemistry consultant and instructor for the American Association for Laboratory Accreditation. She is based in Ohio.